Pilcure TMT is an ultra fast accelerator for NR, SBR, BR, NBR and other highly unsaturated rubbers and most preferred primary accelerator for sulphur cured low unsaturation content rubbers like Butyl rubber (IIR) and EPDM.
Pilcure TMT is widely used as a secondary accelerator with thiazole / sulphenamide class accelerators to achieve faster curing rate and higher cross link density with a compromise on scorch safety. Pilcure TMT contains approx. 13% available sulphur for cross linking and hence, can be used in low sulphur / sulphur less EV cures of diene rubbers. Pilcure TMT does not liberate ‘free sulphur’ during sulphur less cures and the vulcanizates exhibit excellent heat and compression set resistance.
Pilcure TMT is very active at temperatures above 120°C and particularly in NR based compounds, when used alone, exhibits very short scorch time, faster cure rates and marching modulus with development of high cross link density at normal to high sulphur levels. Decrease in sulphur levels improves scorch safety and helps to control the cure rate as well as cross link density.
In SBR based compounds, Pilcure TMT exhibits faster scorch and cure characteristics with relatively broad curing range and flat plateau effect. Semi-EV, EV (low sulphur / sulphur less) cure systems based on Pilcure TMT are often used in NBR based compounds to achieve stringent requirements of heat and oil resistant vulcanizates with lower compression set values. In case of polychloroprene and other halogenated rubber compounds, Pilcure TMT acts as a retarder.
Normal dosages of Zinc oxide and Stearic acid are necessary for Pilcure TMT accelerated cure systems and small proportions of aldehyde amine, DPG, DOTG, ZDC, etc. can further activate the cure rate. However; often retardation of Pilcure TMT based cure systems is desired and the same can be achieved by using sulphenamide or thiazole class accelerators as the conventional acid retarders are not effective. Sulphenamide and thiazole accelerators control the ‘scorching’ and ‘blooming’ tendency for Pilcure TMT based Semi-EV/EV cures without significantly affecting the cross link density and offering practical cure cycles.
As a secondary accelerator Pilcure TMT is very effective with thiazole and sulfenamide accelerators for achieving faster cure rates and good scorch resistance and the vulcanizates exhibit lower heat build-up as compared to DPG / DOTG activated sulphenamide cures.
In case of rubber to metal bonded products along with thiazoles Pilcure TMT is the preferred secondary accelerator as compared to other basic accelerators like DPG, ZDC etc.
Pilcure TMT and / or Pilcure ZDC are non-staining and non-discoloring and also do not impart any taste to the vulcanizates and hence often preferred for the manufacture of rubber products intended for repeated contact with food/drugs. (it may be noted that the FDA rules and regulations are subject to change and seeking clarification from relevant authorities is recommended before commercial manufacture of rubber products).
Pilcure TMT as a primary accelerator and as a secondary accelerator in combination with sulfonamide / thiazoles, etc. is extensively used in NR, SBR, NR-SBR/BR blends, NBR,IIR, EPDM and other synthetic rubber based compounds for the manufacture of auto tyres and tubes, cycle tyres and tubes, conveyor / transmission beltings, retreading materials, footwear, hot air cured products and miscellaneous molded and extruded rubber products.
TYPICAL DOSAGES:
Typical dosages of Pilcure TMT based cure systems are given below
|
TYPICAL DOSAGES OF PILCURE TMT
|
|
Product
|
Rubber
|
Accelerator / Sulphur, phr
|
|
TMTD
|
MBTS
|
CBS
|
ZDC
|
ZDBC
|
DPG
|
S
|
|
Auto Tubes
|
Butyl
NR
|
1.0-2.0
2.0-2.5
|
0.3-0.4
1.0-1.3
|
-
-
|
0.2
-
|
-
-
|
-
-
|
1.5-2.0
0.5
|
|
OTR Tubes
|
Bromo- Butyl
|
1.7
|
1.2
|
-
|
-
|
-
|
-
|
ZnO-4.0
|
|
Cycle Tyre :
Treads
Casing
|
NR
NR-BR
NR
NR
|
0.1-0.2
0.2
0.2-0.3
0.05
|
-
-
1.0
0.7
|
0.8-1.0
1.0-1.2
-
-
|
-
-
-
-
|
-
-
-
-
|
-
-
-
0.25
|
2.4
1.8-2.0
2.5
2.5
|
|
Cycle Tubes
|
NR
|
0.1-0.2
|
-
|
0.8-1.0
|
-
|
-
|
-
|
1.5-1.7
|
|
Molded& Extruded Goods
Conventional Cure
Semi EV Cure
EV Cure
|
NR
NR
NR
SBR
SBR
NBR
NBR
EPDM
EPDM
EPDM
NR
SBR
NBR
NR
SBR
NBR
|
0.5-0.7
0.1-0.2
0.1-0.2
0.1-0.2
0.1-0.2
0.2-0.4
0.2-0.4
1.5
0.8
0.8
0.5
0.5
1.5
2.5-3.0
3.0-4.0
3.0-4.5
|
-
0.7-1.0
-
1.2-1.4
-
1.0-1.2
-
0.5
2.0
1.5
-
-
-
-
-
-
|
0.3
-
0.7-1.0
-
1.0-1.2
-
1.2-1.4
-
-
-
1.5
2.0
1.0-1.2
1.0-1.5
1.0-1.2
1.0-1.2
|
-
-
-
-
-
-
-
-
0.8
-
-
-
-
-
-
-
|
-
-
-
-
-
-
-
-
1.0
2.5
-
-
-
-
-
-
|
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
|
2.0-2.5
2.0-2.5
2.0-2.5
2.0-2.2
2.0-2.2
1.5
1.5
1.5
2.0
2.0
1.4
0.75
1.0
0-0.3
0-0.3
0-0.3
|
|
Fast Curing Ebonite
|
NR/ SBR
/ NBR
|
3.0-4.0
|
-
|
-
|
-
|
-
|
-
|
20-40
|
|
Food Contact Products
|
NR/ SBR
/ NBR
|
0.5-0.7
|
-
|
-
|
0.2-0.4
|
-
|
-
|
1.5-2.0
|